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How Is A CGM Different Than A Blood Sugar Meter?

You will know your sugar level and where it is headed.

A blood glucose meter shows your sugar level right now, but does not tell you if it's about to change. A CGM shows if your sugar is about to change and this keeps you safe from going too high or too low. This can also help when you exercise or eat - because you will be ready with a CGM!

These devices save lives and as horrible as I find it being constantly tethered, it has saved me from overnight lows, prolonged highs, and has helped me stay active with very little risk and fewer finger sticks. (I still finger stick a lot).


How Does A CGM Attach To My Body?

Push a button and the CGM is in place.

Each type of CGM comes with a special inserter. You push a button or squeeze the inserter, and a small needle inserts the CGM's tiny sensing wire under your skin. The needle comes out and the tiny wire stays in. Some CGM types are approved by the Food and Drug Administration to be inserted in the abdomen or upper arms, but many people have tried them all over the body with success.

I used to use my stomach for my continuous glucose monitor. Now, I use my forearms, and I like the profile when I wear clothes because I don't have this weird bulky thing on my stomach. It's more out of the way.


How Does It Actually Work?

Magic! Just kidding - amazing technology.

CGMs are small devices that work by inserting a tiny wire under the skin and an adhesive patch holds the external transmitter in place. The tiny wire is less than 1/2 long, and you can't feel it once it is in place. A small transmitter connects to the wire and sends real-time data to the a receiver. Many people use their cell phone to receive the data using an app.

How Much Will It Cost? Does My Insurance Cover It?

Cost depends on insurance, and it's worth knowing.

All of us with diabetes wish it wasn't so expensive to take care of diabetes. Some sensors are cheaper than others, and more insurance companies are covering them. Planning and knowing the cost can help make decisions about whether it is possible to get a sensor.

This is not the equivalent of buying the next best phone. This is medical care. For me, it's a no-brainer to spend more on supplies if it means I'm going to be healthier in the long run.


Do I still need to prick my finger?

You don’t have to (but you might want to)

While it’s important to have your meter onhand for backup purposes, using a fingerstick-free CGM like the Dexcom or Abbott Libre gives you the freedom to go without a meter on occasion. It’s still good to keep a meter and double check if what you’re feeling doesn’t match up with the reading on your sensor.

How much will it cost? Does my insurance cover it?

CGMs are cheaper than they used to be

All of us with diabetes wish it wasn’t so expensive to take care of diabetes. Some sensors are cheaper than others and if you have insurance, there is a very good chance it is covered. In the How to Get a Sensor Guide there is a section about cost and insurance that has some helpful tips and info.

Your health and well being and quality of life is priceless so if you can afford it, it is worth it


Which one is right for me?

It depends.

The CGM that is right for you depends on where you want to put it on your body, whether you want alerts when you are going too low or too high, and weather you want it to communicate with an insulin pump. For example, if you do not feel your lows or want an alert that tells you when you’re low (or will be soon), then choose one with alerts (Dexcom or Medtronic). If you do not need alerts and can feel your lows, try the Abbott Libre. Our device comparison and check-up questions can help you decide what is right for you.


Almost fingerstick-free
Two of the three sensors available don’t require finger sticks! You still want to have a meter with you, in case, but you won’t need it hardly as much.

Prevent lows and highs before they happen
A CGM shows you which direction your blood sugar is headed and how fast. Some types will alarm during the day or night to help alert you when you have a low or high blood sugar.

Notice Patterns and Adjust Insulin Having sensor data gives you the ability to see patterns that happen over time. You can look at it with your doctor to adjust insulin, food and exercise routines.


Alerts and alarms
Some people get overwhelmed with too many alerts sounding from their devices. You can tailor them to fit your needs and wants, or turn them off entirely (except the emergency low alarm).

Attachment to devices
Wearing a CGM means you will have a device on your body at all times. They’re all waterproof and very durable. Some CGMs have receivers, and others can be linked to a smartphone, which can reduce the number of devices you have to carry!


The work required to maintain a sensor day-to-day is a lot less hassle and pain than checking with a meter.


Look at your numbers when you want to or need to. If your sensor needs a fingerstick to calibrate it - that happens 2 times per day.
It is best to calibrate in the morning or when your blood sugar is not rising or falling quickly.


Change Sensor
This is something you have to do every week, 10 days, or 2 weeks depending on your CGM system. There are also some tips and tricks that might help them last even longer..

3 Months

Order new Sensor Pack
The number of sensors you receive will depend on your CGM system and insurance coverage. But remember, if one rips off or gets damaged before it is supposed to be done, call to get a replacement.

6 Months

Order new Transmitter
The transmitter runs out of battery after a certain amount of time.